Second AC unit trips breaker

Bolter303 · 09-15-2010, 08:36 PM

Hello. I am new her and have a 2008 Raptor 3712. I had a second AC unit installed. When I am at the camp ground the second unit trips the breaker. I am hooked up to 50 AMP service and only run the two AC's and a couple of fans. The RV is at Parker AZ and the temps were 115 one weekend and 120 the next. Is the temp causing this to happen, why does the main AC unit not trip as well. Not sure if there is a wiring issue or not.

Thanks,

Don
Las Vegas NV

Jim W · 09-16-2010, 04:01 AM

There are a several reasons for a breaker to trip in a electrical panel.

1. The breaker is not rated for the amperage that is being used thus causing an overload condition. Such as a 15 Amp breaker but 20 or 30 amps is required for the A/C unit to start.

2. There is a short some where in the wiring. Such as a wire is grounding some were between the A/C unit and the breaker.

3. There is a short in the A/C unit itself.

The A/C circuit breaker is tripping first, thus preventing the entire system from seeing this overload and or this incorrect grounding condition. Just like your home electrical system. A circuit breaker and or a fuse will fail first if it is overloaded and or a short exist.

Are you familiar with a Multi-meter and how it works? If you are then I would trouble shoot the wiring to see if a short exist. Also check the rating on the circuit breaker to ensure that it is at least a 20 AMP circuit breaker.

If you do not feel confident doing this work. Then call a A/C Tec who deals in RV units or dealer to resolve this issue for you.
Jim

**hankpage** · 09-16-2010, 04:22 AM

Also try the unit on a day when demand is not so high. If you are receiving low voltage on that leg of power the amperage use will increase and trip the breaker. Are both A/C units the same size??? If not, see that the larger unit is not wired with other power draws. (water heater especially)

geo · 09-16-2010, 07:12 AM

During prep, our dealer found that the Keystone factory (ordered a second a/c factory installed) had put both A/C units on the same 120V side. On 50 amp service, you have two 120V sides (out of phase) coming in to the trailer. Basically 30 amp a side, but they say 30 - 20. If you have both A/C units on the same 120V side and both are running full out, you will probably pop the circuit breaker. Our dealer switched the front A/C to the other leg before delivery. Just another possibility.

Bolter303 · 09-16-2010, 11:00 AM

I spoke to the dealer that installed the second unit. They want to have it for the day and they will test it and see where the fault is. They said that they need it to trip so they can find out the problem. I will use it this weekend and th tems is said to the 105-108 so we will see what happens. It usuallys trips between 2pm and 5pm which is the hot part of the day. He also said it should be a on a 20 amp breaker. He aslo said that the brakers for the two AC units need to be separated due to heat. So I will update after this weekend.

Bolter303 · 09-17-2010, 06:38 PM

Well it was 110 today and it tripped twice. It only happen between 5-6pm. Also I found the two breakers were side by side and they were very warm. I think if I move them apart it will help.

Bolter303 · 09-19-2010, 05:34 PM

Final Report. I place a fan next to the breaker panel and it blew cool air on it all day. The temps was 108-110 and the breaker never tripped. So I am going to move the tow apart and see if that helps. I has to be a transfer of heat fom the main AC to the second AC breaker.

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